It might be worth noting that your experience can differ from theirs without it being untrue.

I can say that I did Ancient Greece, Romans, Tudors, touched a little on the Spanish Armada before skipping straight to WW2.

Neither of the two schools I attended touched on Colonialism in any recognisable degree, and Slavery was more "We stopped slavery, good job england", when in reality it wasn't done from a place of morality, and instead was driven by mass slave revolts, a decline in plantations culminated by an era of overproduction by slavery, which was leading to economic decline.

I think there was at least some morality at play from the likes of the Quakers, Wilberforce etc. It seems unnecessarily reductionist to say only one or the other force was present, and probably historically inaccurate.

I should clarify my earlier statement, I didn't mean to say there wasn't some form of morality involved, as you pointed out it's likely to some degree there was, just that I don't personally believe it to be a major contributing factor. Just that it was what I was personally taught, that England suddenly realised they were being immoral and sought to right that.

I think it's part of the picture, but like you I wasn't educated enough in the colonial period of British history to have any great certainty.

When we were very young it was the tudors and earlier, then there was a little social history where we covered things like the building of canals and the invention of the spinning jenny, the industrial revolution, enclosure etc, then Cold War history IIRC. Big blank spot where colonial history might have been. You'd think it might be relevant...